1. Technical Field
This invention relates generally to thermal heat shields, and more particularly to wrappable multilayer thermal heat shields.
2. Related Art
Standards for vehicle emissions are becoming increasing strict in reducing the emission of nitrogen oxide and carbon monoxide. In order to facilitate reducing the emission of these gases, many vehicle applications include selective catalytic reduction (SCR) applications, for example. SCR applications typically incorporate conduits for injecting ammonia or urea solutions into the exhaust pipe upstream of a catalytic converter. The injected solution evaporates and mixes with the exhaust gases to create a chemical reaction that will reduce nitrogen oxide and carbon monoxide emissions, and instead produce nitrogen and water. However, in order for the SCR applications to perform efficiently, it is necessary for the exhaust gases that mix with the injected solution to remain at a maximum high temperature; otherwise, the intended chemical conversion of the nitrogen oxide and carbon monoxide gases is adversely affected and inefficient, thereby resulting in unwanted emissions thereof. Accordingly, it is desirable and important to maintain the exhaust gases along the exhaust system upstream and within the SCR system at a maximum temperature.